Problem: If $a + b + c = 6$ and $x + y = -6$, what is $-4a - 4c - 4x - 4y - 4b$ ?
Answer: $= -4a - 4b - 4c - 4x - 4y$ $= (-4) \cdot (a + b + c) + (-4) \cdot (x + y)$ $= (-4) \cdot (6) + (-4) \cdot (-6)$ $= -24 + 24$ $= 0$